A company which makes products for tech giants Apple and Sony has admitted hiring children as young as 14 to work on its assembly lines in China.

Foxconn, which builds gadgets including the iPhone and iPad, said it employed the underage workers as part of an internship programme at a factory in eastern Shandong province.

It issued a statement saying: "This is not only a violation of China's labour law, it is also a violation of Foxconn policy.

"Immediate steps have been taken to return the interns in question to their educational institutions.

"We have found no evidence of similar violations in any of our other campuses in China, but we will not hesitate to take immediate action in any campus if any violations are discovered."

Foxconn is the world's biggest contract manufacturer

Foxconn employs 1.2 million people in China, around 3% of whom are interns.

Geoffrey Crothall, a spokesman for China Labour Bulletin, described them as a "cheap and convenient source of labour" that some vocational schools are happy to provide, as it helps boost their revenues.

"The enterprises tend to be factories that need more hands on the production line," he said. "There is no real training or apprenticeship involved here."